EGCG (Epigallocatechin Gallate): Benefits, Dosage, and Safety

Epigallocatechin gallate (EGCG) is a distinct plant-derived molecule that may help curb inflammation, support weight management, and lower the risk of conditions like cardiovascular disease.

EGCG belongs to a class of plant compounds called catechins, which are a subset of polyphenols. It naturally occurs in several plant-based foods and is commonly marketed as a dietary supplement, often in extract form.

EGCG and other catechins exhibit antioxidant activity that could shield cells from damage caused by free radicals.

Free radicals are reactive molecules produced in the body that can harm cells when their levels rise. Consuming foods rich in antioxidants such as catechins may help limit damage from these molecules.

Some studies indicate EGCG’s characteristics might offer health advantages, such as assisting in lowering elevated blood pressure and aiding weight reduction. Nevertheless, research continues to determine the magnitude of these effects and potential adverse reactions.

Continue reading to explore the potential benefits, dietary sources, and side effects associated with EGCG.

What foods contain EGCG?

EGCG is perhaps most recognized as the main active ingredient in green tea. In fact, researchers often attribute many health effects of green tea to its EGCG content.

Although green tea is a rich source of EGCG, smaller amounts appear in other foods. A 2020 review reports that catechins like EGCG are present in:

• various teas
• cocoa-derived items
• pome fruits such as apples and pears
• prune juice

While much research centers on EGCG as the most active catechin in green tea, other catechins — including epicatechin, epigallocatechin, and epicatechin 3-gallate — might offer similar advantages and are often more prevalent in the diet.

Examples like red wine, broad beans, and a variety of fruits also contain beneficial catechins.

What are the health benefits of EGCG?

Laboratory, animal, and some human studies suggest EGCG delivers health-promoting effects. For instance, a 2020 article indicates catechins like EGCG may help reduce inflammation and lower the risk of several chronic illnesses, including:

• hypertension
• diabetes
• certain cancers

More investigation is needed to clarify how EGCG could be used for prevention or treatment, although current findings are encouraging.

Antioxidant and anti-inflammatory effects

Much of EGCG’s reputation stems from its potent antioxidant activity and ability to combat oxidative stress and inflammation.

Oxidative stress happens when free radical levels are excessive in the body.

Research connects oxidative stress and inflammation with a range of chronic diseases, including cancer, diabetes, and heart disease.

EGCG’s antioxidant and anti-inflammatory actions may help protect cells from oxidative damage and suppress pro-inflammatory molecules like TNF-alpha.

Heart health

A 2022 review suggests EGCG may benefit cardiovascular health by lowering blood pressure, improving cholesterol profiles, and reducing plaque buildup in arteries — all key risk factors for heart disease.

A 2022 animal experiment reported that EGCG reduced blood pressure in hypertensive mice over a 14-day period.

A 2020 systematic review of 3,321 participants across 31 trials found that green tea generally lowered total cholesterol and LDL cholesterol.

A 2023 review also cites research indicating higher green tea consumption is linked to a reduced risk of dying from heart disease.

Although promising, additional studies are needed to determine how EGCG in green tea might specifically lower cardiovascular risk.

Weight loss

EGCG may aid in weight reduction. A 2021 systematic review reported significant decreases in body mass index and waist circumference when people consumed green tea for 12 weeks.

The researchers suggested combining green tea consumption with dietary changes and consistent exercise may help with weight control in individuals with obesity.

Additional human studies summarized in a 2017 systematic review found that taking 100 to 460 milligrams (mg) of EGCG daily alongside 80 to 300 mg of caffeine for at least 12 weeks could produce meaningful weight and body fat reductions.

Still, further research is required to fully understand EGCG’s role in weight management.

Brain health

Animal research in a 2022 review suggests EGCG may:

• enhance cognitive performance
• guard against degenerative brain disorders
• support nerve cell repair

A 2018 review of observational human studies found associations between greater green tea intake and lower risk of age-related cognitive decline, Alzheimer’s disease, and Parkinson’s disease, but the evidence is inconsistent.

A 2019 review indicates that human, animal, and cell studies support the neuroprotective potential of green tea catechins.

Nonetheless, more rigorous research is necessary to determine whether and how EGCG can prevent or treat degenerative neurological diseases in people.

EGCG dosage

Different studies employ varied dosages when evaluating EGCG’s effects.

A 2018 systematic review estimates a 240 milliliter (ml) cup of green tea may contain roughly 187 mg of EGCG, though catechin concentrations can differ widely based on the product and brewing method.

Green tea and its EGCG content are commonly used in traditional Chinese medicine. One 2019 paper suggests EGCG might be tolerated at doses up to 3 grams (g) per day.

However, some reports indicate that very high EGCG doses can cause liver toxicity in animals and humans. Such elevated exposures are more likely when people take green tea extracts or concentrated EGCG supplements.

Most toxicity data come from animal experiments. More clinical trials are needed to define safe intake levels and toxicity thresholds in humans.

Possible side effects of EGCG

EGCG is not entirely without risk. Some research links EGCG supplements to serious adverse effects, including:

• liver and kidney damage
• dizziness
• hypoglycemia
• anemia

EGCG can affect folate metabolism — a B vitamin important for fetal development. Therefore, EGCG supplements should be avoided during pregnancy.

It’s uncertain whether EGCG supplements are safe for breastfeeding people, so it’s prudent to avoid them until more evidence is available.

EGCG may also interact with the absorption or metabolism of some prescription drugs, including certain antipsychotics and cholesterol-lowering agents.

To be safe, consult your healthcare provider before beginning any new supplement.

The bottom line

EGCG is a potent plant compound that may support health by lowering inflammation, aiding weight loss, and reducing the risk of some chronic diseases.

It is most concentrated in green tea but is also present in other plant foods.

When taken as a concentrated supplement, EGCG can cause side effects ranging from dizziness to liver injury. The safest approach is to speak with a healthcare professional before adding EGCG to your regimen to determine whether it is appropriate for you.